I disagree with survivors performing worse when you start getting into the higher tiers of XP. It's true that once you pass 10-15 XP, survivors have upgraded most cards they will ever need, but at that point you should start looking into the exile cards. Stroke of Luck, in particular, is one of the best skill cards you can get. Combine it with Double or Nothing if you can and you can really pack a punch when you need to. Playing on hard difficulty, I've found that Ashcan Pete can easily keep up with a late campaign Jenny Barnes or Sefina deck, and it never feels like I'm dragging behind. I get the impression that exiled cards are often overlooked because people don't like spending unnecessary experience points, but they are definitely worth it once you've upgraded all the cards that you need (which, as I mentioned, happens early when playing survivors).
I also think survivors are more reliant on their investigator ability than most other classes. Their often perceived weaker card list is mitigated by tailoring their deck to accommodate their built in abilities. So when playing Wendy or Aschan, make sure you have plenty of card draws so you can keep using their 'discard a card' ability almost every round. Rabbit's Foot, Take Heart and neutral skill cards will go a long way in making this possible. William, on the other hand, needs to have a lot of assets that you can keep digging out every time you kill an enemy. Preferably, you want assets that will make it easier to keep on killing the next monsters that pops up and thus triggering his ability again. Baseball Bat, Beat Cop and Police Badge are all good candidates for this. Sprinkle in some cheap assets that you can dig up whenever you're low on resources and I've found he performs really well. He won't be able to take down elite bosses as fast as guardians, but being able to replay Leather Coat and/or Cherished Keepsake every time a monster spawns in the mythos phase means he can tank better than most investigators. I can see him having a hard time when playing solo, as you won't see enough monsters spawning, but in two player games and beyond I've always found there are more than enough enemiesto keep him settled.
Maybe I'm a bit off topic, but I felt the need to jump in defense of my darling survivors.

That's a good question. It never occurred to me that those doom tokens would also be removed, but reading in the rule book it says:
"To advance the act deck or the agenda deck, follow these steps, in order: Remove all tokens from the card to be advanced. If the agenda deck is advancing, remove all doom from each card in play"
So I think you're right that the tokens would not be added to the next agenda. Which might just give me the few extra rounds I need to complete the scenario!
Nevermind, further reading has left me unsure again. The removal of doom happens before the agenda flips to side B
Here's the complete order of things:
1. Remove doom
2. Flip Agenda to side B
3. The next card in the deck becomes the current act/agenda
4. The advancing card is simultaneously removed from the game
Since the two last steps happen simultaneously, I'm unsure what takes precedence. but I'm leaning towards the advancing agenda still being the "active agenda" while the text is being resolved (so the doom would be removed along with the card)

I made my first attempt a couple of hours ago.. Managed to kill one out of five, so still a long way to go.
The benefit of challenges like this is that I don't have to rebuild the encounter deck every time I want to solo, I can just leave it ready to play and have a go whenever I feel like it. Lovin' it.

That is how I've been playing it, but I got a little confused when I saw No Stone Unturned.
Maybe it's just an oversight from FFG, that Hiding Spot should've had the same instructions as No Stone Unturned.

From the rules reference, under play action (p. 16), it says:
A card with the fast keyword[...] may be played any time its specified triggering condition is met or, if it has no triggering condition, during an appropriate player window (see “Fast” on page 11).
Under fast actions (p. 11), it says:
A fast event card may be played from a player’s hand any time its play instructions specify. [...]
A fast asset may be played by an investigator during any player window on his or her turn
Now, almost all fast events have a timing instruction, but Hiding Spot does not.
So I guess my question is: What is an appropriate player window for Hiding Spot? Can I play it only during my turn (same as fast assets), or can I play it during any player window during a round?

I see myself as a 60% Ritualist/ 40% Nihilist.
The deck construction aspect of the game is probably my favourite part, and I can spend hours playing around in Arkhamdb. I probably spend somewhere around 7 hours/week on ArkhamDB, on average.
I don't care too much about solving the scenarios as puzzles, so when I replay scenarios it is mostly to test out a new deck idea I've had.
As for when the game starts, there are two things that really gets me pumped: Successfully landing a planned combo/synergy, and when things go terribly, horribly wrong (but still being able to scrape out a win). I find easy games where everything goes according to plan to be anticlimactic and, at times, boring.
My most memorable games have all been when the challenges seem insurmountable, but I manage to eke out a victory despite it all - usually coming down to a single win/lose token draw.
As for play style, I unquestioningly prefer survivors. There's something about turning a bad situation into something favourable that really resounds well with me. Additionally, I find that survivors provoke a diverse deckbuilding pattern, which makes them feel unique to each other in the way they play. I also enjoy playing Sefina and Lola for the same reasons, but over these past couple of years survivors have become my go-to faction.

I include Hiding Spot in most of my survivor decks, even combat focused ones. It's a guaranteed evade for 1 resource that can be played anywhere at any time. I usually use it to bail out a friend who has no chance of evading or fighting a monster, or to give our fighter one more turn to put out some damage. It also allows us to focus on the scenario boss and ignore the smaller monsters if just need to grab the win.
In a Wendy deck it can be an absolute beast if you've got her medallion out, so you can re-use it every turn.

During my playthroughs with Calvin I find that buying Devil's Luck early helps alot against the inevitable bad draw you're going to get.
You will suffer some XP-loss due to exiling it, but it's usually worth it to keep Calvin in the game once he's become a monster.